Pulp-stone burr



T. w; WARD AND' B. F. MELLEN.

PULP STONE BURR.

APPLICATION FILED AUG,5| 1921- 1 ,4]. 9,785 Patented June 13, 1922.

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PULP STONE BURFL' APPLICATION man was. 192].

1,419,785. I Patented June 13,1922.

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- 'IIIIHIIIIIIIII.-1IIIIIIIIIIIA 'IIIIIIIIIIIIIIIIIIIIIII THOMAS V7. WARD, CF WATERTOWN, AND BERT IF. MELLEN, OF FELTS MILLS, NEW

YORK.

PULP-STONE BURR.

Specification of Letters Patent. p m t J 13 192 Application filed August 6, 1921. Serial No. 490,346.

To aZZ whom it may concern:

Be 1t known that we, THOMAS W. lVARD and BERT F. MELLEN, citizens of the United States, residing at IVatertown and Felts Mills, respectively, in the county of Jefferson and State of New York, have invented new and useful Improvements in Pulp-Stone Burrs, of which the following is a specification.

The object of the present invention is to produce a means for obtaining a wood pulp in which the fibers shall be longer, finer and more uniform than those secured by stones dressed by the ordinary construction of burrs The most widely used burrs, for this purpose, are those whose cutting ends are straight and which, in the process of sharpening the pulp stones, by virtue of the said straight ends of the teeth, in its travel across the face of the pulp stone, will break out the edges of the impressions, leaving a very rough surface on the face of the stone, thus weakening the fiber of the wood and breaking the said fibers into short lengths. In carrying out our invention, we propose to produce a burr whose ends shall be tapered to such degree that the same will allow the burr to travel across the face of the pulp stone without breaking out the edges of the impression and wherein a smooth print on the face of the pulp grind stone is obtained.

The drawings illustrate a satisfactory em bodiment of the improvement reduced to practice, and wherein Figure 1 is a view of a portion of a pulp stone showing on the left hand side thereof a dressing burr of the ordinary construction, and on the right hand side thereof a dressing burr in accordance with this invention.

Figure 2 is a sectional view through the stone and burr shown on the left hand side of Figure 1.

Figure 3 is a similar view through the stone and burr shown on the right hand side of Figure 1. V

Figure 4C is a greatly enlarged approXi mately central longitudinal sectional View through a burr in accordance with this in- 'vention.

Figure 5 is a fragmentary enlarged end View thereof.

Figures 6, 7 and 8 illustrate the burr provided with different types of teeth, in accordance with this invention.

On the left hand side of Figure 1, and in Flgure 2, we have illustrated a dressing burr of the ordinary construction and the manner in which the grind stone is treated thereby. The burr is caused to travel over the face of the grind stone when the latter rs revolved in the usual manner.v The burr is lndlcated by the numeral 1, and the holder therefor by the numeral 2. The burr 1 has its teeth of a uniform length, width and thickness throughout. The consequence is that straight shoulders are provided upon the ends of the teeth, and these shoulders acting upon the stone tend to break out the edges of the impressions made thereby, also causing a roughness in the said impressions, as indicated by the numeral 3 in the said left hand side of Figure l of the drawings.

A burr, constructed in accordance with our invention is indicated broadly by the numeral 4-, the same being supported for turning on a holder 5, similar to the holder 3. The burr includes an inner core and an outer facing, the latter, of course, being in the nature of a ring or cylinder and is constructedof metal. For distinction, the outer casing is indicated by the numeral 6, and the teeth thereon by the numeral 7. The teeth, at the ends thereof are gradually tapered inwardly,- as at 8. In this manner, no abrupt shoulders are left at the ends of the teeth, and the said teeth can freely enter the impressions without the liability of breaking the edges thereof, as the ends of the teeth are not directly brought into contact with all of the walls of the impressions, the said ends guiding the "teeth proper therein, and the teeth proper acting upon the stone after being properly guided by the inclined ends thereof will produce a clean cut, as indicated by the numei-al 9 on the right hand side of Figure l of the drawings.

In Figure (3, we have illustrated the burr casing provided with teeth that have only one of their ends tapered inwardly, as at 10. This construction may be found desirable in some instances, while in Figure 7, the teeth are centrally depressed, as at 11. In Figure 8, the teeth of the burr are cut to provide a shoulder 12 at approximately the center of the burr, and the portion of the tooth opposite the shoulder is inclined inwardly below the shoulder, as indicated by the numeral 13. In all of the modifications the ends of the teeth of the burr can freely enter the impressions on the face of the pulp stone without liability of injuring the cor-- 2. A burr, for dressing pulp grind stones, comprising a core having an outer metallic cylindrical facing, a holder on which the burr is revolubly supported, said facing having longitudinal teeth, one or both of the ends whereof being inclined inwardly, and the spaces between the teeth at the said end or ends likewise inclined inwardly, and said teeth. at one portion throughout the length thereof being shouldered and being beveled inwardly to said shoulders.

In testimony whereof we affix our signatures.

THOMAS W. W'ARD. BERT F. MELLEN, 

